Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 755 PM EDT Mon Oct 14 2024 Valid 12Z Fri Oct 18 2024 - 12Z Tue Oct 22 2024 ...Overview and Guidance Evaluation/Preferences... The weather pattern across the Alaska domain will be featured with a surface high situated over the Bering Sea and extending inland across the mainland for the end of the week. A pair of surface lows over the Gulf will likely consolidate into one main low, but most of the bad weather should remain south of the mainland, with the exception of the Southeast Panhandle that will likely be affected going into the weekend. Cold weather is likely for most of the state through Friday and into the weekend, followed by a milder trend early next week. Attention then turns to the western Bering as the next storm system begins approaching the region by late Sunday and into Monday. The 12Z model guidance is in relatively good overall agreement across the Alaska domain for Friday, although there are already some differences in the structure of the low(s) passing south of the Aleutians and then into the Gulf. These differences involve whether there is just one main low, or two separate lows pivoting around each other. Forecast confidence is good over the mainland and the ridge holding over the Bering through Saturday. Looking ahead to Sunday and beyond, models are coming into better agreement for a storm over eastern Siberia with a cold front approaching the western Bering, although there remains some timing and intensity differences in the ensembles, and there will likely be adjustments for timing and/or intensity in future forecasts. The intensity of the main surface low passing north of the Bering Straight has trended stronger compared to yesterday. The ensemble means were gradually increased to about 50% by next Tuesday. ...Weather/Hazards Highlights... A quieter weather pattern is expected across most of the mainland for the end of the week. There will likely be some heavier showers and mountain snow for the southeast panhandle region for Friday into Saturday as the surface low from the Gulf approaches the region. Farther to the north across the Brooks Range and up to the Arctic Coast, periods of snow are likely as an arctic shortwave and surface trough passes through the region, with several inches of accumulation likely by Friday afternoon across northeastern Alaska. Elsewhere across the mainland, mainly dry conditions can be expected through early Sunday. This will likely change with warm air advection ramping up ahead of the Bering Sea system, which will increase coastal rain and Interior snow prospects for Sunday night into early Tuesday. The potential exists for at least a foot of snow for portions of the western Brooks Range, and winds could gust in excess of 40 mph. Temperatures will be rather chilly across most of the state to close out the week and into most of the weekend, with more of an arctic air mass place. Daytime highs will likely be near or below freezing for most inland areas by the end of the week into Saturday, and mid 30s to mid 40s near the southern coast. Some valley locations near the Brooks Range could have overnight lows near zero or even colder by Friday. Warm air advection ahead of the next Bering Sea storm system is expected to result in milder conditions returning to southwestern Alaska by early in the week, with readings rebounding 10-20 degrees for many areas. Hamrick Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html